Department of Nephrology, University of Miyazaki Hospital, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
Dialysis Division, University of Miyazaki Hospital, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
F1000Res. 2020 Aug 11;9:969. doi: 10.12688/f1000research.25597.3. eCollection 2020.
Basal ganglia lesions showing an expansile high signal intensity on T2-weighted MRI are termed the lentiform fork sign. This specific finding is mainly observed in diabetic patients with uremic encephalopathy with metabolic acidosis, although there are also reports in patients with ketoacidosis, dialysis disequilibrium syndrome, intoxication, and following drug treatment (e.g., metformin). A 57-year-old Japanese man on chronic hemodialysis for 4 years because of diabetic nephropathy was admitted to our hospital for relatively rapid-onset gait disturbance, severe dysarthria, and consciousness disturbance. Brain T2-weighted MRI showed the lentiform fork sign. Hemodialysis was performed the day before admission, and laboratory tests showed mild metabolic (lactic) acidosis, but no uremia. Surprisingly, metformin, which is contraindicated for patients with end-stage kidney disease, had been prescribed for 6 months in his medication record, and his sluggish speaking and dysarthria appeared gradually after metformin treatment was started. Thus, the encephalopathy was considered to be related to metformin treatment. He received hemodialysis treatment for 6 consecutive days, and his consciousness disturbance and dysarthria improved in 1 week. At the 8-month follow-up, the size of the hyperintensity area on MRI had decreased, while the mild gait disturbance remained. Considering the rapid onset of gait and consciousness disturbance immediately before admission, diabetic uremic syndrome may also have occurred with metformin-related encephalopathy, and resulted in the lentiform fork sign, despite the patient showing no evidence of severe uremia on laboratory data.
基底节区病变在 T2 加权 MRI 上显示膨胀性高信号强度被称为豆状核叉征。这种特定的发现主要观察到在糖尿病合并尿毒症性脑病和代谢性酸中毒的患者中，尽管也有报告在酮症酸中毒、透析失衡综合征、中毒和药物治疗（如二甲双胍）后观察到。一名 57 岁的日本男性，因糖尿病肾病接受慢性血液透析 4 年，因步态障碍迅速加重、严重构音障碍和意识障碍入院。脑部 T2 加权 MRI 显示豆状核叉征。入院前一天进行了血液透析，实验室检查显示轻度代谢（乳酸）酸中毒，但没有尿毒症。令人惊讶的是，在他的用药记录中，有一种治疗末期肾病的禁忌药物二甲双胍，已经被开了 6 个月的处方，并且在开始二甲双胍治疗后，他的言语迟钝和构音障碍逐渐出现。因此，脑病被认为与二甲双胍治疗有关。他接受了连续 6 天的血液透析治疗，1 周后意识障碍和构音障碍改善。在 8 个月的随访中，MRI 上高信号区域的大小减小，而轻度步态障碍仍然存在。考虑到入院前立即出现的步态和意识障碍的快速发作，尽管患者的实验室数据没有显示出严重的尿毒症，但糖尿病尿毒症综合征也可能与二甲双胍相关的脑病同时发生，导致豆状核叉征。
